Diagnosing appendicitis

I have a new post on Physician's Weekly. My thoughts on diagnosing appendicitis: What works and what doesn’t .

Appendectomy outcomes in the modern era

Finally we have some data on the current rate of complications of appendectomy for uncomplicated appendicitis. But that’s not all. This new paper, published online in the journal Surgery, reveals much about the diagnosis, technique, and outcomes of appendectomy in the United States.

Using data from 115 hospitals participating in the National Surgical Quality Improvement Program, researchers at UCLA analyzed the results of 7778 adult patients undergoing appendectomy for simple appendicitis in 2016.

The decline and fall of the rectal exam

For almost 20 years, the value of the digital rectal exam (DRE), a long time staple of the complete examination of the trauma patient, has been questioned. Performing a rectal examination on all trauma patients is no longer advocated except for a few specific indications.

As recently as two months ago, trauma surgeon Michael McGonigal blogging at The Trauma Pro reinforced the message. Because a rectal examination is so uncomfortable for patients already traumatized and its yield is so minimal, he advocates doing it in only patients with spinal cord injury, pelvic fracture, and penetrating abdominal trauma. For a more extensive discussion of the topic, see Life in the Fastlane, an emergency medicine blog.

Perforated appendix not seen on CT scan

From an email received two days ago. Posted with permission and edited for length and clarity.

I came across your blog while looking for information on something puzzling that happened to my sister. I read the blog on CT scans and appendicitis* and went through all of the comments section. I couldn't find a case like my sister’s.

She has been sick off and on for the last two months. It began with what seemed like a bad stomach virus, fever, throwing up, diarrhea, gas pain, bloating, and stomach cramps. She brushed it off as a 24 hour type thing, stayed home from work a few days, and felt better but never returned to normal. She would have intermittent stomach upset and began to have weight loss. About 3 weeks ago, she went to see her GP who ran some tests (antibody tests, no CBC, chem 7 or normal work up) and diagnosed her with gluten intolerance.

What to do when a normal looking appendix is found at surgery for appendicitis

For patients undergoing surgery with a presumptive diagnosis of appendicitis in Norway and other parts of Europe, the protocol is if the appendix looks grossly normal in the operating room, it is usually not removed.

This approach was mentioned as part of a paper on the readmission of post-appendectomy patients from Oslo University Hospital. Most of the patients underwent laparoscopy based on clinical diagnosis with only 160 having CT scans and 67 having ultrasounds.

Of the 710 patients in the Oslo series, 94% of the appendectomies were done laparoscopically, and 111 had a normal appearing appendix at laparoscopy. The appendix was not removed in 88. The other 23 patients had appendectomies for various reasons, and those appendices were normal at pathology.

The cumulative rate of operating for what turned out to be a normal appendix (88 + 23 cases) was 15.6%, which the authors attributed to “the low use of preoperative CT” due to concerns about radiation exposure. That over 100 patients had unnecessary general anesthesia and surgery was apparently not a concern.

Irrational fear of CT scans in appendicitis

By Skeptical Scalpel and Saurabh Jha*

Simple appendicitis cannot be distinguished from complicated appendicitis by clinical examination and laboratory findings say Finnish investigators. They looked at data from their randomized prospective trial of antibiotics vs. surgery for treatment of appendicitis and concluded that only CT scans could reliably differentiate the two entities.

The study involved adult patients from 18 to 60 years old; 368 of whom had uncomplicated acute appendicitis and 337 had complicated appendicitis—appendicolith, perforation, or abscess.

Duration of symptoms, C-reactive protein, white blood cell count, and temperature were significantly different between simple and complicated appendicitis patients. However substantial overlap of values meant they were not helpful in predicting the presence of complicated appendicitis.

Receiver operating curves for C-reactive protein and temperature areas under the curve do not exceed 0.77. Combining these parameters did not improve accuracy.

The paper concluded that CT scanning is essential in diagnosing acute appendicitis and identifying simple and complicated cases.

A companion study by many of the same authors looked at 1321 patients who presented with clinical and laboratory findings of possible appendicitis. Since their protocol called for confirmation of the diagnosis, all patients underwent CT scans, and 351 (27%) did not have appendicitis.

1 in 20 Americans are misdiagnosed every year

Really?

A paper published in April found that about 12 million Americans, or 5% of adults in this country, are being misdiagnosed every year. This news exploded all over Twitter. Anxious reports from media outlets such as NBC News, CBS News, the Boston Globe, and others fanned the flames.

The paper involves a fair amount of extrapolation and estimation reminiscent of the "440,000 deaths per year caused by medical error" study from last year.

Data from the authors' prior published works involving 81,000 patients and 212,000 doctor visits yielded about 1600 records for analysis.

A misdiagnosis was determined by either an unplanned hospitalization (trigger 1) or a primary care physician revisit within 14 days of an index visit (trigger 2).

A quote from the paper [Emphasis added] : For trigger 1, 141 errors were found in 674 visits reviewed, yielding an error rate of 20.9%. Extrapolating to all 1086 trigger 1 visits yielded an estimate of 227.2 errors. For trigger 2, 36 errors were found in 669 visits reviewed, yielding an error rate of 5.4%. Extrapolating to all 14,777 trigger 2 visits yielded an estimate of 795.2 errors. Finally, for the control visits, 13 errors were found in 614 visits reviewed, yielding an error rate of 2.1%. Extrapolating to all 193,810 control visits yielded an estimate of 4,103.5 errors. Thus, we estimated that 5126 errors would have occurred across the three groups. We then divided this figure by the number of unique primary care patients in the initial cohort (81,483) and arrived at an estimated error rate of 6.29%. Because approximately 80.5% of US adults seek outpatient care annually, the same rate when applied to all US adults gives an estimate of 5.06%.

Aortic dissection leads to man's death in the ED: His wife's perspective

A woman wrote to me about the day her husband died. I have edited her email for length and clarity and changed some insignificant details to protect her anonymity as she requested.

Joe passed away outside in the parking lot while they were getting on a helicopter for transport to a hospital equipped to do his surgery.

He had presented to the ED in terrible pain with lots of thrashing and writhing. His right hand was very cold. His right arm tingled to the point of hurting bad. The vision in his right eye was cloudy, and his hearing was muffled on the right. This was in addition to being very pale and diaphoretic upon admission. This is when I felt a dissecting aorta should have been suspected.

I don’t recall the vitals in the beginning, but they were changing and his blood pressure was dropping very fast. As soon as they finished the EKG-in the first 5 minutes of the visit, I asked the doctor about John Ritter's death [the actor died of a dissecting thoracic aneurysm in 2003]. First I asked if he could check for the condition that caused John Ritter's death. I called it an abdominal aortic aneurysm. The doc corrected me and said that it wasn’t an AAA it was a dissected aorta. I said OK, then check for that. This was 1 hour before the CT scan that led to his diagnosis.

Uncertain diagnosis or CT scan radiation? Which would you choose?

It is so nice to be right.

To summarize what I wrote almost 4 years ago, here and here—based on my experience, patients and families will accept the theoretical risk of a future cancer if it means they'll get an accurate diagnosis.

A recent study validates that opinion.

MedPage Today reports that before receiving any recommendation for CT scanning, 742 parents of children who presented with head injuries were surveyed by researchers from Toronto's Hospital for Sick Children.

Parents, almost half of whom had previously known that CT scanning might cause a cancer to develop in the future, were told of the radiation risks of CT scanning in detail. The authors found that although the parents' willingness to go ahead with the CT scan fell from 90% before the explanation of risk to 70% after they were briefed about radiation, at crunch time only 42 (6%) of them refused to let their child be scanned.

And of the 42 who initially refused, 8 eventually went ahead with the scan after a physician recommended it.

So to put it another way, even after they were fully informed of the potential risk of CT scan radiation to their child (lifetime risk of cancer is about 1 in 10,000, according to the authors), nearly all parents opted for the scan.

Also of note are the following:

The median age of the children was 4.

12% of the children in the study had undergone at least one previous CT scan.

97% of the children were diagnosed with only concussions or mild head injuries.

An article in Scientific American puts some of the radiation risk into perspective. It is long, but worth reading as it explains how risk has been calculated, the best guess as to the true level of risk, and what radiologists are doing to lower the radiation exposure associated with CT scanning.

According to that article, "Any one person in the U.S. has a 20 percent chance of dying from cancer [of any type]. Therefore, a single CT scan increases the average patient's risk of developing a fatal tumor from 20 to 20.05 percent."

No one ever comments about weighing the potential harms that may have been prevented by a timely CT scan diagnosis against the radiation risk.

CT scans should be ordered judiciously. The area scanned and the amount of radiation should be limited as much as possible.

But if you need a CT scan to help diagnose your problem, go ahead and have it.

Bottom line. When it comes to accuracy in diagnosis vs. radiation-induced cancer risk, parents overwhelmingly chose the former.

Is ultrasonography overrated? A radiologist thinks so

In response to an article in the New England Journal of Medicine that discussed whether bedside ultrasonography (US) should be taught to medical students, radiologist Dr. Saurabh Jha recommended that clinicians do a proper history and physical instead of point-of-care ultrasound.

His post appeared on the KevinMD website.

As if a radiologist advising doctors to do an H&P wasn't shocking enough, Dr. Jha then confessed that he thinks "ultrasound images look like a satellite picture of a snow blizzard."

He worried that rather than finding hidden pathology, indiscriminate use of US by inexperienced physicians will simply lead to more and more testing.

Even seasoned radiologists tend to overcall abnormalities on US said Dr. Jha. This leads to increased use of other imaging studies, most of which turn out to be normal. Using US to avoid the risks of ionizing radiation often results in patients having CT scans anyway.

In the comments section of the post, Dr. Jha emphasized that he was talking about situations where the pretest probability of finding something wrong is very low. Directed US based on clinical indications is obviously of value.

Emergency medicine physicians who

Photo via Dr. Ryan Radecki (@emlitofnote)

commented listed several instances which bedside US can be useful such as in identifying pericardial effusions and fluid or blood in the abdomen of trauma patients.

Ultrasound is clearly the test of choice for right upper quadrant abdominal pain. There is nothing better for identifying gallstones, but thickening of the gallbladder wall and fluid surrounding the gallbladder are best seen with US done in the radiology department.

Probing all body cavities with a transducer for no specific indications is another matter.

Is there still a role for a good history and physical examination in modern medicine? Yes.

Is US a useful test? Yes, in the proper context, it can be very helpful.

Should every medical student be taught how to do bedside US? I don't think so. A course is just the beginning. Learning how to perform US requires a lot of repetitions. Many medical specialists will never use it.

I agree with Dr. Jha that the time should be used to "Teach them to organize their thoughts coherently."

What's your opinion?

Note: These folks also tweeted the photo.@EM_Educator @MDaware @EBMGoneWild @choo_ek

Crowdsourcing medical advice

A website called "CrowdMed" offers "crowdsourcing" of medical diagnoses. You enter a narrative about your illness and the crowd, which may not necessarily all be MDs, comes up with a diagnosis for you. Patients are supposed to discuss the most likely diagnoses with their own physicians. Via a somewhat complex system, the medical detectives can win money if patients offer cash rewards, which are not mandatory.

CrowdMed takes 10% of any money put up by patients as its commission. They claim they and anyone who offers an opinion are not legally liable since all medical opinions are anonymous, patients are told that only their real doctors can provide a definitive diagnosis, and all diagnoses are based on the pooled input of many contributors.

I have a friend who has knowledge of medical crowdsourcing that antedates CrowdMed.

He knows someone who is into self-abuse like marathons, triathlons, etc. She always has some ache or pain and goes to a massage therapist or a chiropractor, who offers a diagnosis. Then it’s off to the natural food market for some organic potion. The person behind the counter does the prescribing and maybe a bit of fine-tuning of the diagnosis. Friends and acquaintances are also free to lend their expertise. The most highly prized diagnosticians are wives of doctors, especially those who belong to the garden club. The patient would never consider a recommendation to see an actual doctor.

He has no data on the accuracy of the diagnosticians or the outcomes of the patients.

I was going to ask who in their right mind would ask a bunch of anonymous strangers for medical advice, but then I remembered that I had recently written a post about the people who ask me about their undiagnosed abdominal pain. It turns out there are a lot of such people. 

On the CrowdMed website, most of the cases described are indeed true mysteries. Take this one for example:

Keturah, 39 years old, Oregon, United States—who describes symptoms in 11 different areas of the body using a mere 1689 words.

I wouldn't know where to begin to solve that one.

Unlike the combination of the massage therapist, chiropractor, natural food market clerk, and the doctors' wives, CrowdMed claims it has an 80% success rate in achieving a correct diagnosis.

When I started writing this post, I had intended to ridicule CrowdMed, but I have changed my mind. They may have found a way to monetize what I've been giving away for free. They also have a classically good business model which involves having other people do the work.

A lawyer tries (unsuccessfully) to take down Skeptical Scalpel

A trial lawyer named Max Kennerly has taken issue with a piece I wrote called "Can defensive medicine ever be stopped?" It appeared last week on KevinMD.

On his blog, he he says defensive medicine is a "myth" and accuses me of many wrongs, too numerous to detail here.

I will address a few of them.

He read my post but apparently did so selectively. He failed to note that I agreed with him that tort reform did not reduce the cost of medical care in states that have enacted it. This was documented by a paper from the National Center for Policy Analysis which I cited.

He went on to criticize three brief examples of defensive medicine that I mentioned in my post—about abdominal pain, a wound infection after colon surgery, and chest pain.

Mr. Kennerly writes, "a young girl with lower abdominal pain gets an ultrasound for appendicitis (among the least invasive, least expensive, and most helpful tests in history — remember this funny GE ad for their portable ultrasound?)."